Rick Schuster

I replaced the main coolant radiator because I was getting coolant and transmission fluid mixing and it was showing up in the overflow. I still appear to be getting transmission fluid leaking some how into my coolant still.

So my question is: If the radiator is brand new. The transmission oil goes from the transmission through the radiator into the transmission cooler than back to the transmission again. It appears I may have a very small leak of transmission fluid......."But Where and How?"
Confused, any possible solutions?

Also how about bypassing the transmission cooler if we do no towing?
There is no transmission fluid leaking from the transmission cooler or transmission lines that I can see.

Is changing the transmission cooler the only option, and if so why?

It has been suggested by the Auto Parts store that the new radiator is defective! They will replace it, now this seems like the only viable reason! Do you agree! Or is there some other possibility?

1997 Grand Cherokee 5.2L v-8

Thanks for the help!!
Rick

Gee oh Dee

That does seem odd. If the only place the coolant and trans fluid cross is the radiator that's gotta be your source.

You could bypass it and use an adtermarket cooler.

ct67_72

are you positive its transmission fluid? they typically leak the other way because there is more coolant pressure than oil pressure from the cooler.
There could also be residual trans fluid left in the cooling system.
The best way to tell would be to remove the cooler lines from the radiator all together and install a stand alone cooler.
You can also test for this easily 2 ways.
1. remove trans cooler line. use a rubber tip blow gun and pressurize the trans cooler in the radiator, with the cap off see if you get any bubbles.
2. remove the cooler lines, and either put a pressure pump on the radiator, or loop the cooler lines and run the engine, see if you get any coolant out of the trans cooler.

kjc

[QUOTE=Rick Schuster;1423271]I replaced the main coolant radiator because I was getting coolant and transmission fluid mixing and it was showing up in the overflow. I still appear to be getting transmission fluid leaking some how into my coolant still.
So my question is: If the radiator is brand new. The transmission oil goes from the transmission through the radiator into the transmission cooler than back to the transmission again. It appears I may have a very small leak of transmission fluid......."But Where and How?"
Confused, any possible solutions?

You said you replaced the radiator.. did you flush the cooling system thoroughly? Including the heater core and coolant reservoir? Getting a new radiator with a leak between the radiator and the transmission cooler IS possible, but i'd think it would be too big of a coincidence. Sounds like residual tranny juice in there to me.

Bustedback

If you have any amount of coolant in the transmission you can expect a costly transmission rebuild in the very near future. The coolant will destroy the bonding agents on the friction plates in the clutch packs.

Rick Schuster

GReat responses TY!
I accounted for the idea that there would be some residual transmission fluid in the system, since I did not flush it.
Am I sure the fluid is transmission fluid? Well, there is no mistaking pepto-bismo gravy!!!!
Here is a few things I noticed.
1. the transmission fluid was down again....noticeably down as though it was leaking!
2. the engine and transmission was warm, I had the radiator cap off and as I watched the coolant, here would come a (what I will call a polop or luquid terd) of pink. Then another about 4 seconds apart, on right ofter another and it continued and continued like clockwork. Just like there was a small leak tiny leak, that allowed so much fluid to enter the coolant, like it was a pumping cycle.
3. I will have to say, the residual left over was a far amount, but not that much. I allowed the system to drain for24+hours the amount I had in the over flow was quite significant. I attempted to drain coolant out of the pep-**** on the bottom of the radiator and all I was getting was coolant. So that was a good sign. But after driving it for 60 miles, I should have been able to clean the majority of the risidual out. But it just keeps coming, so I am going with the idea, I have a defective new radiator. The auto parts man told me in 12 years in auto parts he has run across it about 3 times. So I can happen!

I am going to change the radiator again...since they guarentee it. I will let you know how it turns out!!

Thanks All!!

Rick

Marcus Edmonds

replace the radiator and crunk it up drove it for about 5 mins. Then got home and milky stuff was pouring out transmission.. pulled the dipstick and it's covered in milky... The oil looks fine though..... Please help

Cherryokee

Marcus, "Draining" your cooling system is not effective in this case. It is not the same as "flushing" your cooling system. You must also do a full transmission fluid flush-and-fill. You would do better if you did a full transmission and torque converter drain-out with filter replacement. Otherwise, you're doing more harm than good to your transmission by repeatedly driving it with that crappy soup in it. This is one of those "pay me now or pay me later" situations that you read about...

dave1123

In the old days, we'd do a caustic soda flush of the cooling system if any oil of any type got into it, but today with aluminum radiators that would eat holes in them. What you need is an aluminum-safe chemical flush to break up the oil and get it out.

jon-d

good suggestion Dave. he could make up his own using simple green I would think.

dave1123

Yeah, any good low-sudsing detergent would work. It's got to be strong enough to emulsify the oil without foaming the flushing water enough to cause hot spots in the engine.

Srenae90

I have a 97 jeep Cherokee laredo, and noticed that there's transmission fluid mixing in the radiator. I didn't notice it until I had already drove about 15 minutes to the store...
Will it be OK to drive it home like that?? I don't have another vehicle, and dint have anyone to call for a ride this late